[Icecast] Making icecast stream available outside my network?

[Matt Turner]

Hi, i'm a newb to using icecast.
what i'm using is, foobar2000, with the altacast encoder.
I went in to the config file, and changed the adminname/password.
i've  left everything else at there defaults.
I open up altacast, and add a new encoder, giveing it the user name, and 
password.
it works fine.
But when giveing the link to people to listen, they say they can't open it.
I've read up on the doc, but still can't seem to figure it out.
Using NVDA, witch is a screen reader, and windows 8.1.